Frozen water is known for its low friction properties. Most often, frozen water (e.g., snow) constitutes the low friction transport surface on a mountain side. At other times, the same frozen water in the form of ice constitutes the low friction transport surface in a skating setting. The low friction aspect of ice becomes the basis for skiing, sledding and many other winter sports. Ice has a high compressive strength but is generally not structurally stable by itself because it has a low tensile strength (about 1/10 the compressive strength). Ice melts over 32° F. and yields continually under strain. Glaciers vividly demonstrate this.